An Ohio woman said classmates dumped a bucket full of feces, urine, and spit on her autistic son – who believed he was taking part in the ALS “ice bucket challenge.”

The mother said she found video of the incident on her 15-year-old son’s cell phone, reported WJW-TV.

“He was embarrassed because he did not know what the contents were until afterwards and then he didn’t want anybody to know,” said the boy’s mother, identified only as Diane. “They used his phone to tape it and they put it up on Instagram.”

Diane reported the incident to police, who are investigating, and she said she publicized the case to make other parents aware of the bullying.

“The bucket challenge is supposed to be raising awareness for this disease and now they’ve turned it into a sick joke,” said the victim’s mom. “I just can’t understand why kids would do something this cruel.”

Participants in the ice bucket challenge record video of themselves pouring cold water over their heads, make a donation to the ALS Foundation, and then post the video on social media.

In the prank video, the Bay High School student stands in front of a garage wearing only underwear as a bucket containing bodily fluids and cigarette butts is poured over his head by someone on the roof.

“It’s disturbing to watch, you can obviously tell that somebody has been taking advantage of there,” said Detective Kevin Krolkosky, of Bay Village police.

Police said they have a good idea of the other students involved, and the teens could face juvenile charges.